1. Field of the Invention
In general, the present invention relates to molding tools. More particularly, the present invention relates to adjustable and removable trimline inserts for a "cavity half" and a "core half" of a molding tool.
2. Description of the Related Art
Great steps have been made over the past several years in molding technology. Workpieces for various industries are now formed by injection molding, resin transfer molding (RTM), low pressure molding, SMC, and RIM/SCRIM tools. While the actual workpiece forming technology has made great strides, the precision with which the edges and comers of the molded workpieces are made has been lacking. Laser technology has been used to burn defined edges in newly molded workpieces, but the technology is cost prohibited and not easily adapted to industrial settings. To save on time, manufacturers have simply replaced the entire molding tool when its shear edges have become worn. Alternatively, manufacturers have welded smooth the workpiece engagement area of the molding tool thereby filling in a trench that is created by repeated contact with the workpiece.
A further limitation in the art of molding technology is that an adjustable stop plate is not provided that can adjust the material thickness of the workpiece from only one side of the molding tool. For example, U.S. Pat. No. 5,387,096 (the '096 patent) to Wieser discloses the use of trim pieces that can adjust the thickness and molded shape of a workpiece. To adjust the shape and thickness, however, requires that the trim pieces be inserted in both the cavity half and the core half of the molding tool. This is highly undesirable in a manufacturing setting which typically has a molding tool that lies flat on a table so that workers have access to only the core half of the tool. Moreover, the '096 patent does not disclose the use of trim pieces for removable shear edges, nor does it disclose altering the width of trimpieces so that part size can be changed.
It is therefore desirable in the art to have a molding tool with shear edges or trimline pieces that are easily removable and replaceable when worn. It is also desirable to have an adjustable stop plate for regulating the material thickness of a workpiece that is accessible from one side of the molding tool.